Conventional shore-to-shore transportation of large quantities of cargo requires the use of large ships and deep harbors to accommodate for large ships. Because of their size and load, cargo carriers tend to consume a significant amount of energy. Generally speaking, the prior art does not teach energy efficient cargo transportation vessels having shore-to-shore capabilities for transporting large quantities of cargo, particularly ships capable of entering shallow harbors. Regarding sea trains, known arrangements of coupled ships involve flexor connectors, in which the loads on these connectors are as high as one half of the weight of a module. The prior art does not teach high-speed connectorless sea trains.